In the past, popcorn has been popped in microwave ovens with somewhat limited success. One approach has been to apply microwaves for a fixed period of time. This approach typically resulted in a substantially large number of unpopped kernels if too short or in scorching of the popped popcorn if the fixed time period was too long for the specific batch of popcorn placed in the oven. Because of the batch to batch variability, a fixed period of time that is optimum for one batch may over or under-cook another batch of the "same" type of popcorn.
Another approach has been to instruct a microwave oven user (for example on instructions on the container of popcorn specifically packaged for microwave popping) to listen to the popcorn popping and shut the oven off when popping slows down. For example, one instruction says to stop microwave when rapid popping slows to two to three seconds between pops. That same instruction says that the time will range from two to five minutes. This approach requires that the microwave oven user be present during the entire popping cycle and further that the user focus close attention to the popping. This method also suffers from variability in that the user is unlikely to precisely time the two to three second interval resulting in user-to-user variability and even batch-to-batch variability with the same user, at least until that user has acquired the experience to know when to stop the oven.